Sorry, but my thoughts, too. I suspect more men-men and men-women are indulging in anal sex. The rectum isn’t designed to accept an erect penis. It is constructed of delicate cells designed for secretion. The vagina is designed for the rigors of sex.....it is lined with cells that are tougher and made for protection. Obviously, not all colon and rectal cancers are because of this. But the colon cancer rate is higher in gay men than in straight men.
That may be the case with rectal cancer. Rectal cancer is, I believe, usually caused by the HPV virus, which is the same virus responsible for the most common cause of cervical cancer. The HPV virus is sexually transmitted.